4-Aminosalicylic Acid → 2-Hydroxy-4-iodobenzoic acid

HRID 636768Notes

Reaction equation

HRID 636768 reaction equation
N[C:2]1[CH:10]=[CH:9][C:5]([C:6]([OH:8])=[O:7])=[C:4]([OH:11])[CH:3]=1.N([O-])=O.[Na+].[I-:16].[K+]>O.S(=O)(=O)(O)O.[Cu]I>[OH:11][C:4]1[CH:3]=[C:2]([I:16])[CH:10]=[CH:9][C:5]=1[C:6]([OH:8])=[O:7]

Participants

7

Reactant 3

HCID 46494-Aminosalicylic AcidHCID 4875Potassium IodideHCID 23668193Sodium Nitrite

Product 1

HCID 728742-Hydroxy-4-iodobenzoic acid

Reagents, catalysts & solvents 3

HCID 24350Copper(1+) iodide; Copper(I) iodide; Cuprous iodide; Cuprous iodide (CuI)CatalystHCID 962WaterSolventHCID 1118Sulfuric AcidSolvent3×

Conditions

Temperature
-10 °C

Procedure

To 20% sulfuric acid solution (650 ml) were added 4-amino-2-hydroxybenzoic acid and 200 ml of 20% sulfuric acid solution. The solution was cooled to −10° C. and a solution of sodium nitrite (47 g, 0.34 mol) in water (100 ml) was added over 5 hours. The solution obtained was added dropwise to a suspension of potassium iodide (69.5 g, 0.42 mol) and copper(I) iodide (69.5 g, 0.36 mol) in 370 ml of 20% sulfuric acid. The mixture was stirred for 36 hours at room temperature and was then filtered. The filtrate was extracted with ethyl acetate, washed twice with saturated sodium sulfite solution and twice with water. The organic phase was concentrated on a rotary evaporator under vacuum at 40° C. The properties of the final product were as follows:

Workup

  1. customThe solution obtained
  2. filtrationwas then filtered
  3. extractionThe filtrate was extracted with ethyl acetate
  4. washwashed twice with saturated sodium sulfite solution and twice with water
  5. concentrationThe organic phase was concentrated on a rotary evaporator under vacuum at 40° C

Sources & evidence

ORD record
ord-ae4eb9620ee54085b3d9f1976a040c0d
Source dataset
uspto-grants-2001_02
Patent number
US06194450B1

Reaction notes

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